A little, but less than most people expect. In a randomised trial of women past menopause who were new to lifting, raising protein from the recommended amount to about half as much again added no extra muscle or strength over ten weeks; the training itself did most of the work13.
That is one small trial, and the wider evidence says much the same. The extra protein did bring a small extra gain in two fast walking tests.
What was studied
The clearest direct test is one Brazilian trial, reported in two papers13. It enrolled women at least one year past their last period who had done no resistance training in the previous six months. Resistance training means making muscles work against a load, such as weights or machines. The women were aged about 62 to 65 on average3.
Forty-seven women were randomised into two groups. Both did the same supervised training three times a week for ten weeks. Both received an individual diet plan from nutritionists, set to match each woman's energy needs. The only planned difference was protein3:
- Recommended group. About 0.8 g of protein per kg of body mass a day, the RDA (recommended dietary allowance, the official daily amount for adults).
- Higher-protein group. About 1.2 g per kg a day, with the extra from ordinary foods such as meat, fish, eggs, milk and other dairy.
Food diaries showed the groups did differ: about 0.85 g against 1.17 g per kg a day3.
| What | Detail |
|---|---|
| Women | 47 randomised, 23 finished |
| Status | at least 1 year past menopause, new to lifting |
| Training | supervised, 3 times a week, 10 weeks |
| Protein eaten | about 0.85 vs 1.17 g per kg a day |
| Measured | lean mass (DXA), strength, walking and balance tests |
Lean mass is everything in the body except fat and bone; most of it is muscle and water. It was measured with DXA, a low-dose X-ray scan1.
In plain terms: one realistic test of "eat more protein from food while training", in women past menopause who had just started.
What the studies found
Lean mass rose in both groups, equally. Among the 23 women who finished, lean mass rose in both groups, with no difference between them (P = 0.572)1. The authors' title says it plainly: higher protein "does not improve lean mass gain" compared with the RDA in this setting.
Strength rose in both groups, equally. Leg extension one-rep max (the heaviest lift done once) and grip strength rose in both groups, with no difference between them3. Muscle quality, strength for each unit of lean mass, improved in both groups alike.
Two walking tests were slightly faster with more protein. In the six-minute walk, average speed rose from 1.6 to 1.9 metres a second in the higher-protein group and stayed at 1.7 in the recommended group. The 400-metre walk showed the same pattern: 1.7 to 1.9 against 1.7 to 1.73. Both tests asked the women to walk as fast as they could. Shorter tests at usual pace, balance and sit-to-stand showed no difference between groups. The authors rated all these changes as a low effect size3.
Fast walking speed before and after 10 weeks of training, by protein group · m/s
Before After
The authors' conclusion: a moderate increase in protein gave "a small additional improvement in functional capacity, but not in strength" or lean-mass quality3.
In plain terms: training built muscle and strength in both groups; the extra protein showed up only as slightly faster fast walking.
Why more protein did not add more
The trial cannot say why, but two lines of evidence fit.
Untrained people and older people respond less to extra protein. A 2018 meta-analysis pooled 49 randomised trials (1,863 healthy adults) that added extra protein on top of the diet during resistance training2. On average, the extra protein increased gains in fat-free mass by 0.30 kg (95% CI 0.09 to 0.52), a modest amount, and one-rep-max strength by 2.49 kg (0.64 to 4.33). The effect was smaller with increasing age and larger in people who were already trained2. The women in the menopause trial were untrained; the trial's authors raise this themselves3.
There is a ceiling. In the same meta-analysis, gains in fat-free mass stopped rising beyond a total protein intake of about 1.6 g per kg a day2. Both groups in the menopause trial were below that, so the trial did not test the higher end.
For how protein targets are set in general, see how much protein per kg. For what training alone does after 50, see can you build muscle after 50.
What this does and does not mean
- It does not mean protein does not matter. Both groups ate at least the recommended amount. The question tested was whether more than that adds extra, over ten weeks.
- It does not settle higher intakes. The trial compared about 0.85 with about 1.17 g per kg; nobody here ate 1.6 g or more.
- Training was the common factor. Every gain in lean mass and strength appeared in both groups, and both groups trained.
- Women respond to training as well as men. On the same program, relative muscle growth is similar between the sexes (see do women build muscle as fast as men).
- Individual questions. For anyone with a medical condition, including kidney disease, a doctor is the right person to ask about protein intake. The trial excluded women with kidney disease3.
The studies at a glance
| Study | Who was studied | Key result | Year |
|---|---|---|---|
| Rossato et al., *Nutrients*1 | 23 women past menopause (finishers), 10 weeks of training | Lean mass rose in both groups; no difference between 0.8 and 1.2 g/kg | 2017 |
| Morton et al., *Br J Sports Med*2 | 49 trials, 1,863 healthy adults training | Extra protein added 0.30 kg fat-free mass and 2.49 kg 1RM strength on average; less with age | 2018 |
| Nahas et al., *Nutrients*3 | 47 women past menopause, same trial, all randomised | Strength rose equally; fast walking speed rose more with more protein | 2019 |
| Walter et al., *Sports Med Open*4 | 34 studies, 1,541 women past menopause | Training changed body composition and strength; extra protein rarely added more | 2026 |
Limits worth knowing
- About half dropped out. Of 47 women randomised, 23 finished3. The 2019 analysis filled the gaps with statistical imputation; the results were the same without it.
- Small and short. Ten weeks, one trial, two papers. Longer effects are unknown.
- Food records. Intake came from food recalls, and both groups under-reported energy; the authors think protein was less affected3.
- Population. Untrained women past menopause, without hormone replacement, kidney disease or orthopaedic limits3. Results may differ in women who already lift.
- Abstract only for two. We read the 2019 trial paper and the 2026 review in full; the 2017 paper and the 2018 meta-analysis we read as abstracts.
Latest research
The newest study we opened is a 2026 systematic review of 34 studies in 1,541 women past menopause4. Strength training on its own consistently changed body composition, strength and bone density. Nine studies added extra protein to training, by diet or by a daily protein serving, for 8 to 24 weeks. Only one of the nine found a difference between groups, in strength gains; the others found none for any outcome4. The authors conclude that the evidence for extra nutritional strategies on top of training "remains inconclusive". The review received no funding.
How the evidence on extra protein with training built up
- 2017Rossato et al.Women past menopause: lean mass rose equally at 0.8 and 1.2 g/kg a day.
- 2018Morton et al.49 trials: extra protein added modestly to fat-free mass; less with age.
- 2019Nahas et al.Same trial: strength equal; slightly faster fast walking with more protein.
- 2026Walter et al.9 studies in women past menopause: 1 found an extra effect of protein.
The short version
- In women past menopause who were new to lifting, training raised lean mass and strength over ten weeks.
- Eating about 1.2 instead of 0.8 g of protein per kg a day added no extra lean mass or strength in that trial.
- The higher-protein group walked slightly faster in two fast walking tests, a small effect.
- Across nine studies, extra protein rarely added anything measurable to training alone.
Educational overview only — not medical advice.
